Sunken Lesson Animal Growth and

Heredity

Sunken Lesson Animal Growth and

Heredity

How Organisms GrowHow 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.

Cell DivisionCell 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.

MitosisMitosis

• 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

RegenerationRegeneration

• 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

Asexual ReproductionAsexual 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

Sexual ReproductionSexual 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

Life CyclesLife 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

Direct DevelopmentDirect 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

MetamorphosisMetamorphosis

• 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

Complete metamorphosis

Complete metamorphosis

• Complete metamorphosis has four stages: egg, larva, pupa, adult

• Complete metamorphosis has four stages: egg, larva, pupa, adult

Incomplete metamorphosis

Incomplete metamorphosis

• Incomplete metamorphosis has three stages: egg, nymph, adult

• Incomplete metamorphosis has three stages: egg, nymph, adult

Inherited TraitsInherited 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

GenesGenes• 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

Recessive TraitsRecessive 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

Dominant TraitsDominant 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