Sexual and Asexual Reproduction

Learning Outcomes By the end of this lesson, you should be able to:  Define asexual and sexual reproduction.  Describe systems of reproduction in unicellular and multicellular organisms.  Describe mechanisms of reproduction in unicellular and multicellular organisms.

There are two very different ways of reproducing: Asexual reproduction Sexual reproduction Types of Reproduction

Asexual Reproduction in Plants

BULBS Onions Daffodils Look at the examples of asexual reproduction. Can you give a definition of the process? Look at the examples of asexual reproduction. Can you give a definition of the process?

TUBERS Potatoes

RHIZOMES Iris

RUNNERS StrawberrySpider plant

Asexual Reproduction Only involves one parent. Offspring are completely identical to the parent – clones! No gametes (sex cells) are needed. Very safe and easy – no need to find a partner! Common in small/simple animals, plants and bacteria. Also happens in our body all the time – to replace worn out or dead cells. It also happens in some bigger plants.

Asexual reproduction in other organisms

Prokaryotes – binary fission Describe in your own words what is happening in this diagram.

1.Look at some other examples of asexual reproduction on pages Choose one example and draw and annotate a diagram to explain the process. 1.Look at some other examples of asexual reproduction on pages Choose one example and draw and annotate a diagram to explain the process.

Sexual Reproduction

Sexual reproduction involves the production of sex cells called ____________. The gametes are made in the _______________ _______. The process of cell division that produces the gametes is called ___________. In this process, each gamete only receives ___________ the amount of genetic material of the adult cell (haploid). After ______________, this amount is restored to the full number of chromosomes in the fertilised cell (diploid).

The Gametes In the animal kingdom, the male gametes are _________, and the female are _______. In seed-bearing plants, the male gamete is a cell in the _________ ___________, and the female is a cell in the ____________. Male gametes are usually very ___________ in size. They are usually ___________ - making their way to the ovum. Female gametes are ____________ than the male, and are not ____________. The male organism always produces a ____________ number of gametes than the female.

Fertilisation Fertilisation occurs when the two ____________ of the ___________ and ___________ f_____. This forms a new, single cell called a ____________. This cell has a full set of chromosomes = ______. This cell undergoes cell _____________ to develop into an ______________. In plants, after fertilisation the ovule becomes the ___________ and the ovary becomes the ____________.

Sexual Reproduction in Plants

Flower Structure Label the following structures on the diagram: Petal Ovary Stamen Style Stigma Sepal Anther Filament Ovule Carpel

Flower Structure and Function Complete the card sort to match the different floral structures with their functions.

Flower Structure and Function STRUCTUREFUNCTION PetalsBrightly coloured and sometimes scented to attract insects and other pollinators. SepalsOuter protective covering of the flower bud, can be coloured like the petals. AntherProduces the pollen. FilamentHolds up the anther. StamenMale organs, consisting of the anther and filament. StigmaSticky end of the carpel, which collects pollen. StyleThe sperm travels down the style from the stigma to the ovary. OvaryContains ovules. OvuleContains the female nucleus which develops into seeds once fertilised. CarpelFemale organs, consists of the stigma, style and ovary.

Pollen grains

When the flower has been pollinated, the sperms meet the eggs, and seeds form (the offspring!) The ovary turns into the fruit – with seeds inside ready for dispersal. Which of the following are fruits? Vegetables? Are they produced by sexual or asexual reproduction? Fruit or Vegetable?

VEGETABLE! ASEXUAL

FRUIT ! SEXUAL

FRUIT! SEXUAL

VEGETABLE ! ASEXUAL

FRUIT! SEXUAL

FRUIT! SEXUAL

VEGETABLE! ASEXUAL

Fruits always come from a ______. Fruits are made through ______ reproduction! flower sexual Now complete the ‘Sexual and Asexual Reproduction’ summary sheet. Summary

Advantages and Disadvantages AdvantagesDisadvantages Asexual Reproduction Sexual Reproduction Create a table to show the advantages and disadvantages of asexual and sexual reproduction. Watch the video clip to help. Remember: The video is arguing the advantages of asexual reproduction. You will need to think up the advantages of sexual reproduction for yourselves. Create a table to show the advantages and disadvantages of asexual and sexual reproduction. Watch the video clip to help. Remember: The video is arguing the advantages of asexual reproduction. You will need to think up the advantages of sexual reproduction for yourselves.

Sexual Reproduction in Mammals

The Female Human Reproductive System Label the following structures on the female reproductive system diagram: Cervix Vagina Oviduct (fallopian tubes) Ovaries Uterus

Oviduct (fallopian tubes) Ovaries Uterus Vagina Cervix

The Male Human Reproductive System Label the following structures on the male reproductive system: Sperm duct (vas deferens) Seminal vesicle Prostate gland Epididymis Testis Scrotum Penis Bladder Urethra

Vas deferens (sperm duct) Seminal vesicle Prostate gland Bladder Prostate gland Vas deferens Urethra Penis Scrotum Testis Epididymis

Functions Complete the functions table by sorting the functions with their correct structures. Indicate whether the structure belongs to either the male or female reproductive system.

The Female Reproductive System UTERUS: The foetus develops here during gestation. OVARY: Produces ovum. CERVIX: The shorter, narrow portion of the uterus where it joins with the vagina. VAGINA: An elastic, muscular canal that extends from the cervix to the outside of the body. OVIDUCT (FALLOPIAN TUBE): The passage from the ovaries to the uterus. Carries the ovum. URETHRA: The tube which connects the bladder to the outside of the body. In females, it only carries urine. In males, it carries both the semen and the urine, at separate times.

The Male Reproductive System SPERM DUCT (VAS DEFERENS): Transport sperm from the epididymis. EPIDIDYMIS: A narrow, tightly-coiled tube where maturation of the sperms takes place. Connects the testes to the vas deferens. PENIS: Passes either urine or sperms outside of the body. Consists of connective tissue, called erectile tissue, with many blood spaces in it. It allows sexual intercourse to take place. TESTES: Produce sperm and the hormone testosterone. SCROTUM: Sac containing testes. Keeps the testes at optimum temperature for sperm production. SEMINAL VESICLE: Secretes a large proportion of the fluid that becomes semen. PROSTATE GLAND: Stores and secretes a slightly alkaline fluid, which is a constituent of semen. URETHRA