science unit 1 8th grade

Trait

A characteristic that an organism can pass on to its offspring through its genes.

Variation

Any difference between individuals of the same species.

Protein

An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction. The brain of the cell.

What is sexual reproduction?

A reproductive process that involves two parents.

What is produced through sexual reproduction?

A new organism that differs from both parents.

What is combined during sexual reproduction?

Genetic material from two parents.

Fertilization

Fusion of an egg and sperm cell

sex cells

special cells that contain half the number of chromosomes as body cells

Phenotype

An organism's physical appearance, or visible traits.

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Pedigree

A chart or "family tree" that tracks which members of a family have a particular trait

Genes

DNA segments that serve as the key functional units in hereditary transmission.

Alleles

alternative versions of a gene, that gives a different instruction

Genotype

An organism's genetic makeup, or allele combinations.

Karyotype

A picture of all the chromosomes in a cell arranged in pairs

E

allele for extra-big muscles

e

allele for typical muscle

Ee

medium muscle

EE

extra-big muscle

ee

typical muscle

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait

Typical muscle

Homozygous recessive

Extra-big muscle

Homozygous dominant

Muscles

Made up of bundles of cells that move when the bundles relax and contract.

Actin and Myosin

Proteins that slide against each other when muscles contract.

Skeletal Muscles

Look long and striped, or stingy, due to the presence of actin and myosin.

Big Muscled Animals

Most are born big muscled due to their parents being big muscled or being a big muscled breed.

Protein Intake

Eating more protein consistently can help grow muscle mass.

Exercise

Regular exercise contributes significantly to muscle mass and strength.

Trait Variation

Babies with extra-big muscles inherit this variation from their parents.

Chromosomes in Cattle

Cattle are made from 30 chromosomes from the mom and 30 from the dad, totaling 60 chromosomes.

Chromosome Combinations

Different combinations of chromosomes can lead to different muscle sizes in cattle.

Myostatin

A protein that regulates muscle growth; a full myostatin causes normal muscles, while partial myostatin can lead to medium or extra muscles.

Myostatin Receptor

When myostatin fits in the receptor of the cell, it sends a signal to stop making more muscle.

Partial Myostatin

Causes the animal to have medium or extra muscles due to improper fitting in the cell receptor.

Traits

A quality defined by genetics, such as eye color, hair color, skin color, fur color, fur length, paw size, and muscle size.

Chromosome Pairs

Pairs 2, 6, 9, and 22 relate to muscle characteristics in cattle.

Muscle Size Variation

Different chromosomes lead to variations in muscle size, such as extra, normal, or medium muscles.

Genetics of Muscle Size

The genetics of an animal determine its muscle size based on the myostatin present in its chromosomes.

Variation

Different types of the same thing, slightly different types of the same thing.

Protein

Protein is a molecule made up of amino acids, protein helps you build muscles.

Nucleus

A nucleus is like the brain of a cell, it is the center or most important part of a cell.

Sexual Reproduction

A process where a male and a female living thing combine their genetic material to make an offspring.

Sex Cells

Sex cells are the reproductive cells, they contain half the normal amount of DNA.

Phenotype

An observable trait, such as for cows, extra-large muscles or normal muscles.

Chromosome

Chromosomes contain your DNA, they are found in the nucleus of cells.

Pedigree

Pedigree is like an inherited trait, simple symbols that mean specific things.

Genes

A part of DNA, it has instructions for the animal, or living thing.

Alleles

A different type of the same gene, a different type of the same instructions.

Genotype

The genotype of an animal is like their genetics. The genetics of an animal, unobservable traits.

Karyotype

A single or pair of chromosomes, scientists can match them up when they take a picture of them.

Homozygous

An organism with two identical alleles for a specific gene, such as muscle type, inherited from each parent.

Heterozygous

An organism with two different alleles for a specific gene, such as muscle type, with one allele from each parent.

What is muscle hypertrophy?

The increase in muscle fiber size due to increased protein synthesis

What are the main factors that cause muscle growth in animals?

Exercise, protein intake, and genetic factors

What role do proteins play in muscle growth?

Proteins provide amino acids needed to build new muscle tissue through protein synthesis

What happens at the cellular level when muscles experience resistance?

Muscle fibers develop microscopic tears, which trigger protein synthesis to repair and strengthen the muscle

How do hormones affect muscle growth?

Growth hormone and testosterone stimulate protein synthesis and muscle fiber development

Why might some animals naturally have larger muscles than others?

Genetic differences, different activity levels, body size requirements, evolutionary adaptations

What are the limitations of using a simple diagram to show muscle growth?

Cannot show the time process, molecular-level changes, or individual variation