Genetics TEST REVIEW

Genetics TEST REVIEW

Remember

Genetics is the STUDY OF HOW TRAITS ARE PASSED FROM PARENT TO OFFSPRING ...

Heredity is the PASSING OF TRAITS FROM PARENT TO OFFSPRING...

Multiple Choice

What is the passing of traits from parent to offspring?

• heredity

• genetics

• allele

• genotype

Traits->Genes->DNA->Chromosome->Cell

• Traits are characteristics of individuals.

• GENES are segments of DNA- they control traits!n.

• DNA is organized into chromosomes. It is shaped like a double helix (twisted ladder) and is found in the nucleus of a cell.

• Humans have 46 chromosomes (receive 23 from each parent)

• Body Cells (skin, brain, etc)- 46 chromosomes

• Reproductive Cells (sperm & eggs) - 23 chromosomes

Multiple Choice

A segment of DNA that determines the inheritance of a particular trait is a __________.

• chromosome

• gene

• allele

• DNA strand

Multiple Choice

One cat carries heterozygous, long-haired traits (Ll), and its mate carries homozygous, short-haired traits (ll). What is the probability of one of their offspring having long hair?

• 75%

• 25%

• 0%

• 50%

Multiple Choice

In certain dogs, a hereditary form of deafness is caused by a recessive gene "d." A police K-9 officer has a male dog she wants to breed to produce potential police working canines. Naturally, hearing would be essential and necessary to the job for these working dogs.

If the dog is homozygous dominant for the deafness trait and mated with a deaf female, what percentage of the offspring would be expected to hear?

• 100%

• 75%

• 0%

• 25%

Multiple Choice

On which of the following structures are genes located?

• brain cells

• mitochondria

• alleles

• Strands of DNA

Multiple Choice

If the body cell of an organism has 46 chromosomes, how many chromosomes would its reproductive cells (sperm & egg) have?

• 46

• 64

• 32

• 23

Multiple Choice

A segment of DNA that determines the inheritance of a particular trait?

• DNA

• allele

• gene

• chromosome

GENOTYPES

• WRITTEN WITH TWO LETTERS: BB

• Heterozygous/Hyrbid- letters are different Bb

• Homozygous/Purebred- letters are the same BB or bb

• Homozygous dominant- BB

• Homozygous recessive- bb

Phenotypes

• WHAT YOU SEE

• The physical expression of a gene

• Ex: Black Hair, Has Freckles, Brown Eyes

• 
  

• 
  

Multiple Choice

An organism that has two DIFFERENT alleles for a trait is _____.

• heterozygous/hybrid

• homozygous/purebred

Multiple Choice

Which term means "same alleles"?

• heterozygous

• hybrid

• homozygous

Multiple Choice

Which represents a heterozygous trait?

• RR

• rr

• Rr

• NN

Multiple Choice

Another word for heterozygous is ____.

• DNA

• Hybrid

• purebred

• homozygous

Multiple Choice

Which represents a homozygous dominant trait?

• NN

• rr

• Dd

• Rr

Multiple Choice

Hair color, height, eye color, and freckles are all examples of human traits. What do we call the physical expression (what is seen) of the gene?

• phenotype

• genotype

• allele

Dominant or Recessive

• Domiant- always shows, written with CAPITAL LETTERS

• EX: BB

  
  

• Recessive- can be hidden by dominant, written with LOWERCASE LETTER

• EX: bb

Multiple Choice

Which of the following would represent an organism have to inherit in order to have the recessive form of a gene?

• AA

• Aa

• aa

Multiple Choice

In horses, the allele (B) for black coat is dominant to the allele (b) for a brown coat. What phenotypes would result from a cross between a hybrid black horse and a purebred brown horse?

• black & brown

• black only

• brown only

• Bb & bb

• Bb only

Multiple Choice

In certain dogs, a hereditary form of deafness is caused by a recessive gene "d." A police K-9 officer has a male dog she wants to breed to produce potential police working canines. Naturally, hearing would be essential and necessary to the job for these working dogs.

If the dog is homozygous dominant for the deafness trait and mated with a deaf female, what percentage of the offspring would be expected to hear?

• 100%

• 50%

• 75%

• 0%

Multiple Choice

Yellow seeds are dominant over green seeds in pea plants. The letters "Y" and "y" are used to represent the different genes for seed color.

Which genotype(s) represent(s) yellow seeds?

• YY and yy

• YY and Yy

• Yy and yy

• Yy only

Multiple Choice

Mrs. Gibson cannot roll her tongue, but wants her children to be tongue-rollers. If the ability to tongue-roll is a dominant trait, what genotype would her husband need to have in order to give her the best chance of having children who can roll their tongues?

• BB

• Bb

• bb

Multiple Choice

A _____ trait will show regardless of the other alleles present in an organism.

• homozygous recessive

• gene

• recessive

• dominant

Other forms of Dominance

• Codominance- when the forms BOTH SHOW,

• Incomplete Dominance- When the forms BLEND/MIX together.

Multiple Choice

What allows a black chicken and a white chicken to have a black and white speckeled chicken?

• codominance

• incomplete dominance

Multiple Choice

What allows a red flower and a white flower to have pink offspring?

• codominance

• incomplete dominance

Multiple Choice

If a cross between a red flower and a yellow flower produces an orange flower, which of the following are true?

• codominance has occurred

• incomplete dominance has occurred

• Red flowers are hybrids

• Being red is recessive and orange is dominant

Multiple Choice

One cat carries heterozygous, long-haired traits (Ll), and its mate carries homozygous long-haired traits (LL). What is the probability of one of their offspring having short hair?

• 0%

• 33%

• 50%

• 100%

Multiple Choice

One flower is heterozygous red (Rr) and it is crossed with a homozygous white (rr) plant. What is the probability of one of their offspring having a red color?

• 0%

• 25%

• 50%

• 75%

Multiple Choice

One flower is homozygous white (rr) and it is crossed with a homozygous red (RR) plant. What is the probability of one of their offspring having a red color?

• 75%

• 25%

• 100%

• 0%

Mutations, Adaptations, and Acquired Traits

• Mutation- A Change in the DNA of an organism. Can be helpful, harmful or neutral

• An adaptation is any physical or behavioral change that helps an organism survive.

• An Acquired Trait is one that a person learns/gets/or acquires from his/her environment. EX: learning Spanish, learning to sing, playing an instrument

Multiple Choice

Which of the following best describes a mutation?

• occurs when a dominant trait masks a recessive trait

• the breaking down of the nuclear membrane

• the resulting traits of incomplete dominance

• any change in the genes of an organism

Multiple Choice

Mutations can be

• helpful

• harmful

• neutral

• helpful, harmful, and neutral

Multiple Choice

______ occurs when genes from one organism are changes and/or inserted into the genes of another organism.

• selective breeding

• genetic engineering

• mutation repair

Multiple Choice

The diversity among dogs, such as the ability to herd or differences in body shape, is the result of

• selective breeding

• genetic engineering

• gene manipulation

• bio-medical resarch

Multiple Choice

In Mendel's pea experiments, the forms of the gene for height were "T" and "t." What are different forms of a gene known as?

• Genes

• Alleles

• Traits

• Chromosomes