Genetics Biology Test

Study Guide

Heredity

Passing of traits from parents to offspring

F1 (first filial)

Crossing individuals of the Parental generation

Phenotype

the appearance of an organism's trait.

Genotype

genetic make-up an organism gets

ESSAY - Why did Gregor Mendel choose the garden pea plants for his genetic studies?

Small size, grew fast, many offspring, traits were in contrast.

In meiosis ____ are formed from ____ cells in which chromosomes ____ from their homologous pair to form ____ and sperm that are _____.

Gametes, diploid, segregate, eggs, haploid.

ESSAY - What does the Theory of Segregation say?

Alleles of each pair separate independently of one another during gamete formation. This causes traits to disappear and reappear from generation to generation.

ESSAY - What are true-breeding plants?

plants whose offspring have only one for of a trait.

rr is an example of

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homozygous recessive/purebred

RR is an example of

homozygous dominant/purebred

Rr is an example of

Rr is an example of

heterozygous/hybrid

Gametes have how many chromosomes?

haploid the number of chromosomes as all the other cells of an organism

ESSAY - What does the Chromosomal Theory of Inheritance state?

The genes on chromosomes are the units of inheritance

Meiosis produces eggs and sperm (gametes or sex cells), each being haploid (n) with ____ the chromosome number.

half

In humans, the which gender determines the sex of the child.

male

Males have ____ sex chromosomes

XY

Females have ____ sex chromosomes

XX

When segments of DNA in chromosomes exchange DNA with each other during prophase I of Meiosis I, _____ occurs.

crossing over

_____ has 2 separate cells divisions, I and II, resulting in 2 _____ cells at the end of division 1 and 4 ____ cells at the end of division II.

meiosis, haploid, haploid

____ and _____ occur in Meiosis

segregation, independent assortment

ESSAY - What is the Law of Independent Assortment?

Genes for one trait assort themselves to gametes during Meiosis I independently of other genes for other traits

Haploid cells are first produced from diploid cells in _____

Meiosis I

ESSAY - Why are mutations rare in human populations? (3 reasons)

usually occur on recessive alleles, mutations on genes occur infrequently, two people who marry will unlikely both carry a mutation for the same trait

Down Syndrome (Trisomy-21) individuals have a total of ____ chromosomes. They have three #21 chromosomes.

47

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Because the color blindness gene is located on the X chromosome, the male gender is more commonly color blind than the female gender. Therefore, it is considered a _____ trait linked to gender.

sex-linked

Type A: Only ____ antibody clumps or agglutinates it.

A

Type B: Only ____ antibody clumps it.

**B**

Type AB: Both ____ antibody clumps it.

A and B

Type O: ____ antibody clumps it.

neither A nor B

Antibodies clump the blood when they react with the same ____ on the red blood cell membrane.

Antigen marker protein

ESSAY - Diseases that are genetically caused may be cured in the future by what treatment?

Gene Therapy

mutations

gene changes that can be inherited

Karyotype

chromosomal makeup of a person.

What is the Rh factor

1 gene with 2 alleles, RH+ is dom and produces RH blood antigen, but no RH blood antibodies. RH- is recessive and produces no RH antigen.

ESSAY - Explain what the Human Genome Project is designed to do.

Trying to find every gene in all 46 chromosomes of the body.

What happens in male sex tests?

Y chromosome glows. Stain cells of the umbilical cord glow in UV light

Pros to genetic engineering?

meds, soil fertility, cure genetic disorders, plant and animal hybrids, cleaning environment

Sickle cell and anemia in Africans (Ss)

SS: no sickle cell, may get malaria

Ss: no sickle cell AND no malaria

ss: sickle cell and die.

Know down syndrome traits on paper

okay

What does gene therapy involve

replacing a defective with a healthy gene

point 

affects one of only a few nucleotides

frameshift

insertion or deletion of a nucleotide

What could happen if an RH- mother X RH+ father has RH+ child?

1 - mom makes RH antibodies to fight the antigens off. 2 - they attack the baby's RH antigens and baby could die.

What does Rhogam Meds do for the birth?

keeps RH antibodies from baby by never producing them

Why would you need a sex test?

olympics

What happens in female sex test?

Barr bodies. One of the 2 X chromosomes that is tightly coiled stains darkly.

How is genetic engineering done?

vitro (test tube)

cons of genetic engineering

defective individuals, undesirable mutations, resistance to medicines

What is the Human Genome Project and what is it trying to do.

Trying to locate and sequence every gene in all 46 chromosomes of the human body.

Turner's Syndrome

XO (45 chromosomes), female gender, sterile, but hormones correct this, 65% miscarried, 1/3000 

Klinefelter's Syndrome

XXY (47 chromosomes), male gender, feminine characteristics, and sterility, treated with hormones. mentally disabled, 1/400