Chapter 23 Biology Test
How many chromosomes are in a humans gametes?
Each gamete contains only 23 chromosomes
How many chromosomes are in each somatic cell in humans?
Each somatic cell has 46 chromosomes
What is hybrid?
organism with two different alleles for a particular trait and a cross between two different species of organism
What is Oogenesis?
production of egg cells in the female
What is Spermatogenesis?
production of sperm cells in the male
What does a carrier do?
receiving a CF gene from only a parent makes a child a carrier and a person carries a recessive gene for genetic diseases
What is Asexual Reproduction?
requires only mitosis cell divisions and includes budding, direct outgrowth, and fragmentation
What are genetics?
scientific study of heredity
What is dominant trait?
show up in the offspring even if an allele for a different trait is also present
What is haploid?
sperm cells contain half the usual of chromosomes and also the egg cell
What is a phenotype?
the appearance of the individual and a purebred and a hybrid appear the same for the dominant trait
What is a genotype?
the combination of genes for a particular trait
What is diploid?
the complete number of chromosomes
What are Homologous Chromosomes?
they are similar in size and shape and contain the genetic codes for the same functions
What is recessive trait?
trait doesn't show up when the dominant allele is present
Genetically, what is the difference between a person with sickle-cell anemia and one with sickle-cell trait?
Sickle-cell anemia makes only abnormal hemoglobin molecules(H2H2 - carries oxygen to your body) and Sickle-cell trait is neither gene is dominant, both express themselves (H2)
What are eugenics?
an attempt to improve the human race through the control of hereditary factors of forced sterilization and breeding
What is a dyhybrid?
an organism that is heterozygous for two traits
What is heterozygous?
are alleles different from the other
Who is referred to as the father of genetics?
Gregor Mendel
What is the difference between F1 & F2 generation?
Gregor Mendel called the first generation of pure bred parents the F1 generation -- F stands for filial, "having to do with offspring"; the second generation of hybrid parents, he called the F2 generation
What are some ways that man's advancing genetic knowledge can be used for good? What are some ways that it can be misused?
It could be used to help the effects and abnormally. It can be misused because through child development and genetic diseases.
What is the purpose of Meiosis? How is this process different from mitosis?
Mitosis - asexual reproduction Meiosis - sexual reproduction The egg and sperm originate in specially designed type of cell division which occurs in ovaries of females and the testes of males. Meiosis allows for exchanging of genetic info during synapse, mitosis doesn't and mitosis daughter cells are identically the same as parent cell. Meiosis, daughter cells are different genetically from parent cells and different from each other.
What is a Female's sex symbol?
XX
What is a Male's sex symbol?
XY
What is alleles?
different forms of a gene for a particular trait, such as various seed colors
What are sex chromosomes?
homologous pairs which determine an organism's sex
What is polygenic inheritance?
involves trait controlled by many different pairs of genes. Example: Skin color and height
What is heredity?
is the transformation of characteristics from parent to offspring
What is homozygous?
organism has two identical alleles for the same trait Ex: HH hh
What is pleiotropy?
most genes influence not just one trait but several seemingly unrelated traits
What is zygote?
when an egg and a sperm unite in the process of fertilization, the result is a single fertilized egg cell
What is synapsis? Why is it significant?
when homologous chromosomes pair up. It exchanges genetic material called crossing over. Leads to greater genetic variety in the gametes
