Name:__________________________________
Subject-Period:___________________________
Date:___________________________________
Unit 4 Study Guide
Answer the following questions ON YOUR OWN PAPER. Use your Unit 4 notes, book, lab and worksheets to
help! Your test will consist of matching and multiple choice questions. MUCH of this test is having a good
understanding of the vocabulary. KNOW YOUR VOCABULARY!!!!! 
1. Define asexual reproduction- The process by which a single organism makes a genetic copy of itself.
2. Define binary fission. Give an example of an organism that would use this type of asexual reproduction.
Binanry fission occurs when one parent splits into two offspring. This is how all bacteria and some
single celled protists reproduce
3. Define budding. Give an example of an organism that would use this type of asexual reproduction.
Budding occurs when a new organism grows off a parent. Simple organisms such as some protists and
some simple eukaryotes reproduce by budding.
4. Define vegetative reproduction. Give an example of an organism that would use this type of asexual
reproduction. Vegetative reproduction occurs when a new plant grows off an existing part of an old
plant. Many plants can use vegetative reproduction. Ivy Grasses, Potato plants, Strawberries, Spider
plants
5. Define sexual reproduction. Sexual reproduction requires two organisms. Each organism has
specialized sex cells called gametes. Animals have sperm (male) and ovum (female). Plants have pollen
(sperm) and ovum (egg). Sexual reproduction happens when the two sex cells fuse together (fusion) to
create a new and genetically different offspring.
6. Define gametes (sex-cells). Give examples of the male/female gametes for both plants and animals.
Gametes are the sex cell- sperm and egg. Animals have sperm (male) and ovum (female). Plants have
pollen (sperm) and ovum (egg). Sexual reproduction happens when the two sex cells fuse together
(fusion) to create a new and genetically different offspring.
7. Define chromosome. Where are chromosomes found? How many chromosomes should a normal
human have? Chromosomes are tightly coiled pieces of DNA. In the nucleus of the cells; 46 (23 pairs)
8. Define DNA. Where is DNA found? DNA is deoxyribonucleic acid. It is the code in which the
instructions for life are written. It is found in the nucleus of cells inside chromosomes.
9. Define gene. Where are genes found? Genes are part of the DNA code of instructions on a
chromosome. Genes code for a certain trait. Inside the nucleus of cells in the chromosomes.
10. Define allele. Alleles are the different forms of each gene.
11. Define dominant. What letters represent a dominant allele? A dominant trait is a trait that is expressed
whenever it is found in the genotype. Dominant traits are shown by capital letters. (A, B, C)
12. Define recessive. What letters represent a recessive allele? A recessive trait is a trait that is only
expressed when both recessive alleles are present in the genotype. (example: pp or tt) Recessive traits
are shown by lowercase letters. (a, b, c)
13. Define “purebred” (hint- same as homozygous). Two of the same alleles (PP or pp)
14. Define “hybrid” (hint- same as heterozygous). Two different alleles (Pp)
15. Define genetics. Who is considered to be the father of genetics? Genetics is the branch of Science that
focuses on heredity; Gregor Mendel
16. Define phenotype. Give examples of a person’s phenotype. A phenotype are the traits you can
physically observe on an organism. Color; Size; Shape
17. Define genotype. Give examples of a person’s genotype. TT; Tt; tt
18. What are the advantages of asexual reproduction? Rapid population growth Requires less energy to
reproduce All organisms are capable of reproduction (not just the females of the species) One organism
can make a whole population Less likely to become extinct Each offspring is a genetic copy of the
parent
19. What are the disadvantages of asexual reproduction? THERE IS NO GENETIC DIVERSITY! This
means that a population of genetically identical organisms is more susceptible to disease and can’t adapt
easily to a changing environment.
20. What are the advantages of sexual reproduction? Sexual reproduction requires two organisms. Each
organism has specialized sex cells called gametes. Animals have sperm (male) and ovum (female).
Plants have pollen (sperm) and ovum (egg). Sexual reproduction happens when the two sex cells fuse
together (fusion) to create a new and genetically different offspring.
21. What are the disadvantages of sexual reproduction? It requires two individuals with opposing gametes
(sex cells). Organisms must use a lot of energy nourishing and growing a new baby organism.
Directions- Please indicate whether each term would be considered “Genotype” or “Phenotype”.
1. Blue eyes _______P__________________________
6. Heterozygous _____G_________________
2. DNA____________G_________________________
7. Freckles ________P___________________
3. Homozygous dominant _____G________________
8. Green wings____P____________________
4. Genes ______________G_____________________
9. Alleles__________G___________________
5. Homozygous recessive ____G_____________
10. Physical appearance____P_____________
Directions- Please tell whether each term would be homozygous dominant, homozygous recessive or
heterozygous.
11. AA = _____HD___________________________
16. aa = _______________hr__________________
12. BB = ______HD_____________________________
17 Zz = ______________HD__________________
13. Ff = ____He____________________________
18. LL = ______________HD_________________
14. mm = ________hr__________________________
19. Mm = __________He____________________
15. PP = _________HD__________________________
20. kk = ________________hr_______________
Directions- Please work each Punnett Square. Give the percentages of each genotype and each phenotype of
the offspring. For each Punnett Square, Purple (P) is dominant and white is recessive (p).
PP x pp
Pp x Pp
Pp
Pp
PP
Pp
Pp
Pp
Pp
pp
Ppx pp
Pp
pp
Pp
pp
_0____% Homozygous Dominant
_25____% Homozygous Dominant __0___% Homozygous Dominant
___0__% Homozygous Recessive
____25_% Homozygous Recessive __50___% Homozygous Recessive
___100__% Heterozygous
___50__% Heterozygous
___50__% Heterozygous
__100___% Purple color
__75__% Purple color
____50_% Purple color
__0___% White color
__25___% White color
__50___% White color.