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Biology 150 Exam 4
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31
Biology
Undergraduate 3
11/20/2013

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Term

How old is the Earth? How long ago did life arise on Earth?

Definition
4.5 billion years, life was 3.5 billion 
Term
What was Louis Pasteur’s contribution to science?
Definition

Spontaneous generation (obsolete body of thought on the ordinary formation of living organisms without descent from similar organisms) refuted

Term

 What important lesson was learned by Miller and Urey’s experiment?    

Definition
Researchers must develop hypothetical scenarios and experiment to determine if steps are chemically and biologically possible and plausible.
Term
What is endosymbiotic theory ?
Definition
The endosymbiotic theory states that several key organelles of eukaryotes originated as symbioses between separate single-celled organisms
Term
What notable changes gave rise to primates? 
Definition
Tree dwelling, binocular vision, including color vision, grasping hands and large brains
Term
What changes gave rise to the hominids?  
Definition
Switch to bipedalism, gradual abandonment of tree-dwelling esistence, increasing brain volume, tool-making abilities 
Term
Describe DNA: What are the major components? 
What is a nucleotide? 
What are the four possible nitrogen bases? 
 What is the structure? 
Definition
nucleotides, Basic units of nucleic acids, Adenine, Cytosine, Guanine and Thymine, A-T, C-G
Term


·      Describe RNA: What are the four possible nitrogen bases? 
 What is the structure? 

Definition
Adenine, Cytosine, Guanine and Uracil, A-U, C-G
Term


·      Who discovered the double helix structure of DNA? 
What was Rosalind Franklin’s contribution? 

Definition
James Watson and Francis Crick,
Pretty much all of it, led to the understanding of the structure of deoxyribonucleic acid. 
Term

 

     What are chromosomes? When do they appear?

What are homologous chromosomes? 

Definition
Chromatin folded up , Mitosis, Same or similar genes
Term
What does it mean for a cell to be diploid? 
Definition
containing two complete sets of chromosomes, one from each parent.
Term

 What is a karyotype? 

Definition

  

·       Pictorial depiction of an organisms chromosomes

Term

 

What are sister chromatids? 

 

Definition
Duplicated chromosomes
Term

 

·      What are mutations? 
 How can they contribute to microevolution?

Definition

Structural alteration, alter DNA structure

be passed to new cells
disrupt the transcription process of protein sythesis

Term

 

Mitosis

Definition

 

Mitosis is the process whereby one cell divides into two identical daughter cells.

Term
What are the functions of mitosis?
Definition
Tissue repair, reproduction, Embryonic development
Term

 

 

Gametic cells:

Definition
Gametes are reproductive cells that unite during sexual reproduction to form a new cell called a zygote.
Term

 

Haploid or diploid?

 

 

Definition
Gametes (egg or sperm) must be haploid, because they must join together (fertilization) to form a diploid zygote, which is the offspring of the two “parents” that produce the gametes. Thus, the zygote has the same chromosome number as the partents, but has the same choromosome number as the parents, but has some characteristics of the mother and some of the father.
Term

 

independent assortment:

When?

 

 

Definition

Independent assortment is the random assortment of chromosomes during the production of gametes, the results are genetically unique individual gametes.

Both occur during prophase I 

 

  

Term

 

 

Definition
Term

 

     Who was Gregor Mendel? How did he contribute to the field of genetics? Btw, what is genetics?

 

Definition

Father of Genetics

 

he deponstrated that the inheritance of certain traits in pea plants follows particular patterns, now referred to as the laws of Mendelian inheritance.

 

 

the study of heredity and the variation of inherited characteristics.

Term

     Different forms of a given gene are called ________. What do the terms dominant and recessive mean? What does it mean for a genotype to be heterozygous? Homozygous?

 

Definition

Alleles

 

Dominant Allele refers to the expressed trait in a pair of genes,while the dormant,suppressed trait is the recessive allele.

 

1 dominant allele and one recessive alleles.

 

 

Alleles are either both recessive or both dominant

Term

 

·             What is a genotype? 

Definition
The genetic constitution of an individual organism.
Term

What is a phenotype? How are they related phenotype and genotype?

 

 

 

 

Definition

The set of observable characteristics of an individual resulting from the interaction of its genotype with the environent

 

Genotype are the genes (Bb/BB) and the phenotype is what is expressed (hair color)

 

 

Both genotype and phenotype determine what traits are passed on from parents to children. However, while genotype is what describes the genome which is about the physical DNA molecules, the phenotype describes the phenome which is about the physical properties like shape, form, color.

Term
What is incomplete dominance? Codominance?
Definition



In incomplete dominance, the phenotype resembles a sort of blending of the two alleles. That is, if you have an allele for red petals and and allele for white petals, you end up getting pink petals with incomplete dominance.

Co-dominance is when both alleles are expressed separately. Human blood type is a good example of this. The A and B alleles are both expressed, so you get the AB blood type. In the petal color example above, you'd get a flower with white and red splotches.

 

Term

 

·             What is polygenic inheritance? Conversely, what is pleiotropy?

 

 

Definition

Polygenic inheritance is when a single trait is controlled by 2 or more sets of alleles. 

 

Pleiotropy refers to the phenomenon in which a single gene controls several distinct, and seemingly unrelated, phenotypic effects. 

Term

 

         Mendel’s Laws: 1) Law of segregation
2) Law of independent assortment.
When do these occur during meiosis? 

 

 

Definition

Segregation: Alleles separate prior to the formation of gametes, or egg and sperm (this is what we now perceive as homologous chromosomes that separate during meiosis)

 

 

independent: individual traits are transmitted without being affected by others (what we now know as the random alignment of chromosomes during Metaphase I of meiosis).

Term

 

Transcription

occurs

in

the

Definition
nucleus
Term

Translation occurs in the.....

 

Definition
 cytoplasm.
Term

    

·              What is a gene? 

Definition
a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
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