Standard 4

Objectives

Students will understand that offspring inherit traits that make them more or less suitable to survive in the environment.

Objective 1: Compare how sexual and asexual reproduction passes genetic information from parent to offspring.

a. Distinguish between inherited and acquired traits. Inherited traits are traits that you get genetically from your parents or "inherit". Examples include: dimples, ear lobe shape, right or left handedness, etc.

Acquired traits are traits that you learn. These do NOT come from your parents. Examples include: scars, playing an instrument, playing a sport, learning a new dance, cooking, sewing, crafts, skateboarding, multiplication tables, etc.

b. Contrast the exchange of genetic information in sexual and asexual reproduction (e.g., number of parents, variation of genetic material).

Sexual reproduction involves 2 parents. It is the joining of an egg and a sperm. The final result is a new organism that is a genetic combination of both parents. Sexual reproduction introduces variety in the species.

Females produce eggs. Males produce sperm. Asexual reproduction involves 1 parent. Offspring are produced identical to parent. They have the exact same sequence of DNA. Think "clone" of parent. The genetic material does NOT change from parent to offspring.

c. Cite examples of organisms that reproduce sexually (e.g., rats, mosquitoes, salmon, sunflowers) and those that reproduce asexually (e.g., hydra, planaria, bacteria, fungi, cuttings from house plants).

Asexual reproduction include these examples: bacteria, hydra, amoeba, planaria, fungi, yeast, sea star being cut in half and each half regrowing into a full sea star, plant cuttings from house plants, etc.

Sexual reproduction include these examples: humans, rats, mosquitoes, insects, dairy cows, salmon, sunflowers, dandelions, clams, dolphins, earthworms, cats, dogs, pollen blowing from one flower to another flower, pollen carried by one insect from one flower to another flower, etc.

d. Compare inherited structural traits of offspring and their parents. Offspring of asexual reproduction will have exactly the same characteristics as parent.

Offspring of sexual reproduction will have same body structure as parents, but will be a genetic combination of both parents.

Examples: Shape of earlobes, dimples, length of toes, bone structure, etc.

Objective 2: Relate the adaptability of organisms in an environment to their inherited traits and structures.

a. Predict why certain traits (e.g., structure of teeth, body structure, coloration) are more likely to offer an advantage for survival of an organism.Bird beaks, Structure of teeth, Body structure Coloration of moths in industrial areas vs. non-polluted area

Know that traits can be inherited or acquired

b. Cite examples of traits that provide an advantage for survival in one environment but not other environments.

Birds in desert survive on soft parts of cactus. Birds with large beaks can crack open and eat hard seeds.

Many animals near the North Pole are white. Organisms with colorful appearances (in a dull environment) warn their predators that they are harmful or do not taste good.

Dolphins, fish, sharks have fins that help them move in water.

Giraffes have long necks to eat leaves off taller trees.

Whales have long bodies to move through the water.

Honeybees have stingers to protect themselves.

Warm fur in a tropical climate. Not good!

If plants or animals cannot adapt, they may move to another location, the population may change over time genetically or eventually become extinct.

c. Cite examples of changes in genetic traits due to natural and manmade influences (e.g., mimicry in insects, plant hybridization to develop a specific trait, breeding of dairy cows to produce more milk).

What is mimicry? One organism imitating or mimicking another. Can be looks, sounds, actions, etc.

What is camouflage? When an organism blends in to their environment.

Mimicry in insects Plant hybridization to develop a specific trait

Breeding of dairy cows to produce more milk

Increased speed for prey animals Increased stealth in predators Viceroy butterfly resembles a monarch butterfly in color to keep from being eaten.

Corn snakes(“red next to black, friendly jack” resemble coral snakes(“red next to yellow, deadly fellow”) in color.

d. Relate the structure of organs to an organism’s ability to survive in a specific environment (e.g., hollow bird bones allow them to fly in air, hollow structure of hair insulates animals from hot or cold, dense root structure allows plants to grow in compact soil, fish fins aid fish in moving in water).

Hollow bird bones allow them to fly in air

Hollow structure of hair insulates animals from hot or cold

Dense root structure allows plants to grow in compact soil

Fish fins aid fish in moving in water

Hummingbirds have long thin beaks to suck nectar

Hawks have curved, sharp beaks and talons for ripping flesh