Unit D - Genetics Flashcards
54 - Investigating Human Traits 55 - Plants Have Genes, Too 56 - Joe's Dilemma 57 - Reproduction 58 - Creature Features 59 - Gene Combo 60 - Mendel, 1st Geneticist 61 - Gene Squares 62 - Analyzing Genetic Data 63 - Show Me The Genes! 64 - Nature and Nurture 65 - Breeding Critters 66 - Patterns In Pedigrees 67 - What Would You Do? 68 - Searching for the Lost Children 69 - Evidence From DNA 70 - Finding the Lost Children 71 – Should We?
Which traits (eye color, tongue roll, finger cross, earlobes, hairline, hand clasp, and PTC tasting) are inherited from parents?
Eye color, hairline, earlobes, PTC (100%)
Tongue roll, finger cross, hand clasp (partial)
True/False: Most traits are impacted by the environment
True
Is the classroom an accurate representation of a larger population (a school or community)? Why or why not?
No… sample size was too small and too similar
Why do we study fruit flies or plants?
- Short generation time (birth to reproductive maturity)
- Produce many offspring
- Easy to obtain/maintain
- Have many observable traits
- Ethical
In generation I, two plants were homozygous green and two were albino (yellow/white). What is the probability of a Gen II plant being green?
100%
What does connective tissue do?
Provides connections from tissue in the body
What are the pros about asexual reproduction?
- Rapid + efficient
- Doesn’t rely on a mate
What is the con about asexual reproduction?
- No genetic diversity - risky for a species
What is an example of asexual reproduction in a unicellular organism?
Bacteria: copy genetic information and divide
What is an example of asexual reproduction in a multicellular organism?
Hydra: budding: offspring grow directly from the parent and break off when they mature
What is the pro about sexual reproduction?
- Genetic diversity
What are the cons about sexual reproduction?
- Does rely on a mate
- Not as efficient
In sexual reproduction, the offspring will be _________ from both of its parents.
different
Identical twins result when–
One fertilized egg cell splits before growth and development
Fraternal twins result when–
Two egg cells are fertilized by two sperm cells
What are some traits impacted by the environment?
Intelligence, height, weight
What is the female sex cell?
Egg
What is the male sex cell?
Sperm
Why is breeding performed?
- Gets desired traits
- Maintains a species
- Study genetics
What are Mendel’s rules of inheritance?
- Offspring inherit an equal amount of genes from both parents
- Two genes for each characteristic
- Some genes are dominant over others
The dominant gene is always expressed by a _______ letter
capital
The recessive gene is always expressed by a _______ letter
lowercase
Who was the first geneticist?
Gregor Mendel
What did Mendel find out?
When two heterozygous things are crossed, the ratio of dominant:recessive is close to 3:1
Why do we not always get a 3:1 ratio when performing a heterozygous cross?
Human error, small sample size
Why did Mendel do so many crosses for the same characteristic?
To improve reliability and to have a higher sample size
Why is it impossible for offspring to show the recessive trait if one parent is homozygous for the dominant trait?
All of the offspring will get at least one dominant allele and will express the dominant trait
Why do unicellular organisms divide?
To reproduce
Why do multicellular organisms divide?
To grow and to replace old, worn out, or dead cells
When do chromosomes appear?
When a cell is dividing
How many chromosomes are in body cells?
46
How many chromosomes are in sex cells?
23
Before a cell divides, DNA is _______
copied/replicated
What is DNA?
Deoxyribonucleic acid
What does DNA contain?
All the information organism needs to grow and function
What is DNA shaped like?
A spiral ladder or double helix
What are the sides of the helix made of?
Sugar (deoxyribose) and phosphate
What are the rungs/steps of the ladder made of?
Nitrogen bases
What are the 4 “puzzle pieces” that match to make DNA rungs?
Cytosine, Thymine, Guanine, Ademine
How do the puzzle pieces always bond? Why?
Cytosine/Thymine and Guanine/Ademine; chemically bond only one way
What is a nucleotide?
A unit of DNA consisting of sugar, phosphate, and a nitrogen base
The 46 chromosomes can be sorted into _______ matching pairs
23
What is a karyotype?
Thing showing all chromosomes of offspring/baby, revealing if there is a syndrome or an odd number of chromosomes
What is an example of a helpful mutation?
Bacterial antibiotic resistance
What is an example of a neutral mutation?
Different nose shape
What is an example of a harmful mutation?
Genetic disease (cystic fibrosis)`
What environmental factor are we testing by using the black petri dish?
Sunlight
What ratio would we expect with a clear dish?
3:1
What ratio did we get in the black dish?
0:22
Can heredity alone ensure that organisms will grow and have a healthy life?
No… organisms such as plants also rely on environmental factors (water) for proper growth.
Can the environment alone ensure that organisms will grow and have a healthy life?
No… some organisms carry mutations
What is a real-life example of incomplete dominance?
A red and white flower make a pink flower
What is a real-life example of co-dominance?
AB blood
What are some traits influenced by the environment?
Intelligence, height, weight
What happens during interphase?
- DNA is replicated
- Growth of cell occurs
What happens during prophase?
- DNA condenses into chromosomes
- Nuclear membrane breaks apart
What happens during metaphase?
- Chromosomes line up in the middle of the cell
- Spindle fibers connect
What happens during anaphase?
- Chromosomes separate and are pulled to opposite ends of the cell
What happens during telophase?
- Nuclear membrane forms around chromosomes
What happens during cytokinesis
- The cells split in two
For a person to be a carrier, does the condition have to be dominant or recessive?
Recessive
What is the genotype of the carrier?
Heterozygous
What does a horizontal line on a pedigree mean?
Marriage or had kids
If the parent’s blood types are O O, what can the child be?
Type O
If the parent’s blood types are A O, what can the child be?
Type A or O
If the parent’s blood types are B O, what can the child be?
Type B or O
If the parent’s blood types are A A, what can the child be?
Type A or O
If the parent’s blood types are B B, what can the child be?
Type B or O
If the parent’s blood types are A B, what can the child be?
Type A, B, AB, or O
What are the possible genotypes for O blood?
OO, because O is recessive
What are the possible genotypes for A blood?
AA or AO
What are the possible genotypes for B blood?
BB or BO
What are the possible genotypes for AB blood?
AB
What does a shaded in circle/square on a pedigree represent?
The person has the condition/disorder
What does a square on a pedigree mean?
The person is a male
What does a circle on a pedigree mean?
The person is a female
How can you determine if a trait is recessive?
If the parents DON’T have it, but the kids DO
How can you determine if a trait is dominant?
If the parents DO have it, and the kids DO OR DON’T
