2. Sunken Lesson Animal Growth and Heredity Grade 5

3. How Organisms Grow Nearly all body cells produce exact copies of themselves. Producing identical cells allows organisms to function properly and grow. Nearly all body cells produce exact copies of themselves. Producing identical cells allows organisms to function properly and grow.

4. Cell Division The nucleus controls everything a cell does and tells it when to divide. Cell division is called mitosis. During mitosis a cell makes exact copies of itself. The nucleus controls everything a cell does and tells it when to divide. Cell division is called mitosis. During mitosis a cell makes exact copies of itself.

5. Mitosis To prepare itself for mitosis, a cell makes an exact copy of its chromosomes During mitosis, the chromosomes pull apart, and the cell membrane pinches in at the middle Two new cells are formed that are identical to the parent cell To prepare itself for mitosis, a cell makes an exact copy of its chromosomes During mitosis, the chromosomes pull apart, and the cell membrane pinches in at the middle Two new cells are formed that are identical to the parent cell

6. Regeneration Regeneration is a kind of healing, or tissue replacement When our skin is damaged, we heal through regeneration of new skin cells Some plants and animals can regenerate major body parts – lizards can grow new tails and starfish can grow new arms Regeneration is a kind of healing, or tissue replacement When our skin is damaged, we heal through regeneration of new skin cells Some plants and animals can regenerate major body parts – lizards can grow new tails and starfish can grow new arms

7. Asexual Reproduction Many primitive organisms such as one celled bacteria reproduce by simple cell division Only one parent is required for asexual reproduction Yeast reproduce by budding – a new bud forms on the parent cell, grows, and then separates to form a new cell Many primitive organisms such as one celled bacteria reproduce by simple cell division Only one parent is required for asexual reproduction Yeast reproduce by budding – a new bud forms on the parent cell, grows, and then separates to form a new cell

8. Sexual Reproduction Most organisms require two parents to reproduce Parent cells go through meiosis to copy its chromosomes and divide Then they go through a second stage of division where they split their chromosomes in half. Gametes are formed with half the chromosomes of the parent cells Two gametes join to form a one new cell Most organisms require two parents to reproduce Parent cells go through meiosis to copy its chromosomes and divide Then they go through a second stage of division where they split their chromosomes in half. Gametes are formed with half the chromosomes of the parent cells Two gametes join to form a one new cell

9. Life Cycles Most organisms grow and mature through several distinct stages of life These stages of life are called life cycles All life cycles start with a young organism Most organisms grow and mature through several distinct stages of life These stages of life are called life cycles All life cycles start with a young organism

10. Direct Development In direct development, the young organisms are identical to the adult organism except for size The young grow larger, but keep the same body features, such as shape, all their lives In direct development, the young organisms are identical to the adult organism except for size The young grow larger, but keep the same body features, such as shape, all their lives

11. Metamorphosis Some organisms change greatly from the time that they are young to the time that they are adults. The changes in the shape or characteristics of an organisms body as it grows and matures are called metamorphosis Some organisms change greatly from the time that they are young to the time that they are adults. The changes in the shape or characteristics of an organisms body as it grows and matures are called metamorphosis

12. Complete metamorphosis Complete metamorphosis has four stages: egg, larva, pupa, adult

13. Incomplete metamorphosis Incomplete metamorphosis has three stages: egg, nymph, adult

14. Inherited Traits Many characteristics of an organism are passed from parent to offspring Hair or fur color, eye color, attached or free earlobes, short or long eyelashes, tongue rolling, and dominant thumbs are examples of traits that are inherited Traits can be dominant, or strong and seen, while others are recessive, or weak and hidden Many characteristics of an organism are passed from parent to offspring Hair or fur color, eye color, attached or free earlobes, short or long eyelashes, tongue rolling, and dominant thumbs are examples of traits that are inherited Traits can be dominant, or strong and seen, while others are recessive, or weak and hidden

15. Genes Genes are structures on chromosomes that are found in a cell’s nucleus Genes contain the code for the traits that an organism gets from its parents Genes are structures on chromosomes that are found in a cell’s nucleus Genes contain the code for the traits that an organism gets from its parents

16. Recessive Traits If a recessive trait (such as light brown fur in a rabbit or blue eyes in a human) is seen, then the organism MUST have TWO genes for that trait. That means that they received the recessive gene from both parents If a recessive trait (such as light brown fur in a rabbit or blue eyes in a human) is seen, then the organism MUST have TWO genes for that trait. That means that they received the recessive gene from both parents

17. Dominant Traits If a dominant trait (such as dark fur or brown eyes) is seen, then the organism only needs one gene for that trait. That means they only had to receive the dominant gene from one parent If a dominant trait (such as dark fur or brown eyes) is seen, then the organism only needs one gene for that trait. That means they only had to receive the dominant gene from one parent