Basics of Biology Chapter 4

2 Developing Shark Embryo

3 Four essential ingredients of life Carbohydrates- sugars and starches, like glucose- good energy source Carbohydrates- sugars and starches, like glucose- good energy source Proteins- Made up of chains of amino acids (have nitrogen in them) Proteins- Made up of chains of amino acids (have nitrogen in them) Enzymes- proteins that speed up chemical reactions in the body Enzymes- proteins that speed up chemical reactions in the body Hormones- chemical messengers in the body Hormones- chemical messengers in the body Lipids- fats and oils, store energy- repel water which is useful for many marine mammals and birds Lipids- fats and oils, store energy- repel water which is useful for many marine mammals and birds Nucleic acids- DNA and RNA, store and transmit genetic information for proteins Nucleic acids- DNA and RNA, store and transmit genetic information for proteins

4 Simple molecules have low energy, complex molecules store energy in their bonds

5 Biochemical reactions Substances are constantly being synthesized (put together) and broken down to store or release energy for living things Substances are constantly being synthesized (put together) and broken down to store or release energy for living things Photosynthesis- capturing the sun’s energy to produce simple sugars Photosynthesis- capturing the sun’s energy to produce simple sugars uses CO 2, releases O 2 uses CO 2, releases O 2 Respiration- breaks down food (sugars) to release energy Respiration- breaks down food (sugars) to release energy uses O 2, releases CO 2 uses O 2, releases CO 2

6 Algae are the main photosynthetic organisms in the ocean- Sometimes it isn’t green due to many types of photosynthetic pigments

7 Respiration The sugars produced by photosynthesis are broken down to release energy for the cells. The sugars produced by photosynthesis are broken down to release energy for the cells. Aerobic respiration- releases the most, and needs oxygen. Aerobic respiration- releases the most, and needs oxygen. Anaerobic- does not release as much energy, no oxygen required. Anaerobic- does not release as much energy, no oxygen required. -organisms that live in sediments or in the guts of fishes. -organisms that live in sediments or in the guts of fishes.

8 Which produce and which eat? Autotrophs- can produce their own food, mostly algae and bacteria in the ocean Autotrophs- can produce their own food, mostly algae and bacteria in the ocean Heterotrophs- cannot photosynthesize, all the animals that eat other organisms Heterotrophs- cannot photosynthesize, all the animals that eat other organisms

9 In photosynthesis, solar energy is converted to chemical energy. -only done by autotrophs In respiration, chemical energy is released for the organisms to use. -both autotrophs and heterotrophs

10 Prokaryotes do not have a nucleus- this one is called a cyanobacteria, it can photosynthesize - bacteria only!!!!!

11 Eukaryotic cells Have a nucleus and organelles Have a nucleus and organelles All the other kingdoms- plant, animal, fungi and protists (algae and some animal- like plankton) All the other kingdoms- plant, animal, fungi and protists (algae and some animal- like plankton) Plant cells- have a cell wall and a large vacuole for storing water Plant cells- have a cell wall and a large vacuole for storing water Animal cells- no cell walls, no large vacuole. Animal cells- no cell walls, no large vacuole.

12 Typical animal cell- no cell wall.

13 Typical plant cell- note the cell wall and the water filled vacuole

14 Levels Of Organization- least complex to most complex Cell- Smallest unit of life, simplest form of life- made of organelles which are made of molecules Cell- Smallest unit of life, simplest form of life- made of organelles which are made of molecules Tissue- cells that are specific for a function Tissue- cells that are specific for a function Organ- tissue organized into structures Organ- tissue organized into structures Organ system- a group of organs that work together Organ system- a group of organs that work together

15 Levels Of Organization- least complex to most complex Individual- a single organism Individual- a single organism Population- a group of the same species living in an area Population- a group of the same species living in an area Community- several populations of different species in the same habitat Community- several populations of different species in the same habitat Ecosystem- the community AND the physical environment Ecosystem- the community AND the physical environment

16 A Sponge is a simple animal at the cellular level of organization. (No specialized tissues or organs)

17 A population of Mussels on a shore in New Zealand.

18 A community of mussels, barnacles and seaweeds

19 Table 4.01

20 Diffusion- movement of molecules from High to Low concentration

21 Osmosis- Diffusion of water into and out of a cell This is a major physiological issue for marine organisms!!!! This is a major physiological issue for marine organisms!!!! Water will always flow towards where there is more solute (salts) Water will always flow towards where there is more solute (salts) Marine organisms have a variety of adaptations to be able to balance water and salts in their bodies. Marine organisms have a variety of adaptations to be able to balance water and salts in their bodies.

22 A cell responding to changes in salinity

23 Osmosis (cont’d) Osmoconformers- Conform to salinity. Their internal salt concentration varies with changes in salinity Osmoconformers- Conform to salinity. Their internal salt concentration varies with changes in salinity Osmoregulators- have special mechanisms for maintaining a constant water/salt balance. Osmoregulators- have special mechanisms for maintaining a constant water/salt balance. Most marine fishes tend to lose water, so they compensate for this by excreting very little water in their urine. Most marine fishes tend to lose water, so they compensate for this by excreting very little water in their urine. They also must excrete excess salts, some salts are excreted through urine, more salts are excreted through the gills. They also must excrete excess salts, some salts are excreted through urine, more salts are excreted through the gills.

24 Figure 4.14a

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26 This Sea Turtle has glands near the eyes that excrete salty “tears”.

27 Temperature All animals are greatly affected by temperature. All animals are greatly affected by temperature. Temperature plays a major role in determining where certain organisms live in the ocean. Temperature plays a major role in determining where certain organisms live in the ocean. Ectotherms or Poikilotherms- cold- blooded Ectotherms or Poikilotherms- cold- blooded Endotherms or homeotherms- warm-blooded. These animals expend a great amount of energy to maintain a stable internal temperature. Endotherms or homeotherms- warm-blooded. These animals expend a great amount of energy to maintain a stable internal temperature.

28 Figure 4.16

29 Modes of reproduction Asexual reproduction Asexual reproduction no gametes (sperm and eggs) are used, offspring are genetically identical to parent. no gametes (sperm and eggs) are used, offspring are genetically identical to parent. Examples- budding, fission, vegetative reproduction. Examples- budding, fission, vegetative reproduction.

30 Asexual Reproduction- fission- the two new cells are clones.

31 Asexual reproduction- budding and rhizomes (runners)

32 Modes of Reproduction (cont’d) Sexual reproduction- combining genetic material of two parents to produce unique offspring. Sexual reproduction- combining genetic material of two parents to produce unique offspring. Sperm and Eggs (gametes) required. Sperm and Eggs (gametes) required. Each gamete has half the number of chromosomes required (haploid) Each gamete has half the number of chromosomes required (haploid) Upon fertilization the new individual has the right # of Chromosomes (diploid). Upon fertilization the new individual has the right # of Chromosomes (diploid).

33 Reproductive Strategies Broadcast Spawning- organisms produce millions of gametes, no further interaction with offspring. Broadcast Spawning- organisms produce millions of gametes, no further interaction with offspring. Most marine species fertilize externally. Most marine species fertilize externally.

34 Photos of a coral spawning and a giant clam spawning

35 Organizing Life’s Diversity Biologists reconstruct the history of life on earth is based upon a unifying concept in biology- Evolution by Natural Selection. Biologists reconstruct the history of life on earth is based upon a unifying concept in biology- Evolution by Natural Selection. Natural Selection- individuals with certain traits give them an advantage in a given environment. Natural Selection- individuals with certain traits give them an advantage in a given environment. These individuals will be more successful in reproducing- ‘favorable’ traits are passed on to offspring. These individuals will be more successful in reproducing- ‘favorable’ traits are passed on to offspring. Evolution is simply the genetic change in populations over MANY generations. Evolution is simply the genetic change in populations over MANY generations.

36 Organizing Life (cont’d) Biological species concept- Populations of organisms that have common characteristics, and can interbreed. Biological species concept- Populations of organisms that have common characteristics, and can interbreed. Naming - We scientifically name organisms with two names the genus and species. Ex. Homo sapien, Naming - We scientifically name organisms with two names the genus and species. Ex. Homo sapien, Tursiops truncatus

37 Phylogeny- reconstructing evolution We use a branched diagram to try and reconstruct the evolutionary past of groups of organisms. We use a branched diagram to try and reconstruct the evolutionary past of groups of organisms. These records are constantly being revised as we learn more about the fossil record. These records are constantly being revised as we learn more about the fossil record.

38 Figure 4.23

39 Probable Phylogeny of the six kingdoms

40 The Tree of Life All organisms are classified into the following categories: All organisms are classified into the following categories: DomainEukarya DomainEukarya Kingdom Animalia Kingdom Animalia Phylum Chordata Phylum Chordata ClassMammalia ClassMammalia OrderPrimate OrderPrimate Family Hominidae Family Hominidae Genus Homo Genus Homo SpeciesHomo sapien SpeciesHomo sapien

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