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3 years ago

Did birds evolve from the gliding reptiles called pterosaurs?

Biology

2 answers:

Law Incorporation [45]3 years ago

5 0

Yes, the pterosaurs is the ancestor of the bird.

kenny6666 [7]3 years ago

3 0

No. Birds are direct ancestors of dinosaurs, having simular trates such as wish bones, hollow bones, and feathers. All pterosaurs went extinct in the k.t. mass extinction. Not to mention pterosaurs flew with the skin connecting their wings to their body, as birds flew with primary flight feathers.

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Were are chromosomes found in an animal cell?

Mademuasel [1]

Chromosomes are found in the nucleusof animal and plant cells.

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3 years ago

Consider the model of the food chain. Imagine a local farm has dumped excess pesticides in the pond used for irrigation. This wi

ElenaW [278]

Answer:

Explanation:

The deposition of pesticides in the bond with result to increase in bacteria that breakdown the chemicals for energy. This provides ‘food’ for bacteriophages and then food for algae that will thrive in the pond. They take up oxygen from the pond and make the waters anoxic. The fish will, therefore, be smothered and their numbers will reduce in the pond.

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3 years ago

Read 2 more answers

It is not always possible to measure every individual in a population; what is the name of the representative group?

ra1l [238]

Answer:

d. sampling unit

Explanation:

Sampling unit:

Refers to the unit or group of elements that are selected from an original population during an investigation. The sampling unit might be composed of a statistical unit or a group of statistical units.

The statistical unit or element is the elemental unit that composes the target population.

The sampling unit is a basic concept to keep present during the development of the investigation project. It is the minimal unit of observation that will be used to take information about the variables of interest. All the sample unit composes the population and is defined by an N, while only some representative sample units compose the sample, and are represented with an n.

So, the whole population can not be measured because of its size, or the individuals´ characteristics, among other many factors. So we need to take a random and representative sample or group of the population to proceed with our investigation. This sample or group is composed of some of the original population individuals, which are defined as "sample units".

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3 years ago

In the following pedigree showing the transmission of Cystic Fibrosis, an

statuscvo [17]

Ff or FFim assuming. since shes normal.

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3 years ago

1. What are Chargaff's rules?

kotegsom [21]

1)Chargaff's rules state that DNA from any cell of any organisms should have a 1:1 ratio of pyrimidine and purine bases and, more specifically, that the amount of guanine should be equal to cytosine and the amount of adenine should be equal to thymine. This pattern is found in both strands of the DNA.

2)DNA structure

DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA's instructions, or genetic code.

3)A nucleotide consists of three things: A nitrogenous base, which can be either adenine, guanine, cytosine, or thymine (in the case of RNA, thymine is replaced by uracil). A five-carbon sugar, called deoxyribose because it is lacking an oxygen group on one of its carbons. One or more phosphate groups.

4)DNA replication is said to be semi-conservative because of this process of replication, where the resulting double helix is composed of both an old strand and a new strand. ... Semiconservative replication would produce two copies that each contained one of the original strands and one new strand.

5)The diagram has show in above.

6)complementary base pairing is necessary because the double helix shape would not be the same if not. Doubles would only pair with doubles and the singles to singles.

HOPE THIS HELPS YOU.

7 0

3 years ago