Acrosomal enzymes (acrosin and MMP2) as well as the enzymes that help establish capacitation, are inhibited by zinc, the accumulation of zinc on the zona pellucida and in the surrounding cumulus form a “zinc shield” that prevents further sperm entry

TLS Online TPP Program

#Id: 3691

#Unit 2. Cellular Organization

The sum of the number of unique genes and the number of gene families is an estimate of the number of types of genes.

The minimum size of the proteome can be estimatedfrom the number of types of genes.

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#Id: 8664

#Unit 10. Ecological Principles

The Enemy release hypothesis is the idea that invasive species are less impacted by enemies than native species.

TLS Online TPP Program

#Id: 4024

#Unit 2. Cellular Organization

Some regions of chromatin are very densely packed with fibers, displaying a condition comparable to that of the chromosome at mitosis. This material is called heterochromatin.

TLS Online TPP Program

#Id: 4775

#Unit 5. Developmental Biology

The P2 cell produces the MOM-2 protein, a C. elegans Wnt protein.

TLS Online TPP Program

#Id: 5511

#Unit 10. Ecological Principles

Populations of some species are prone to extinction for two reasons

1. The landscapes they live in are patchy (making dispersal between populations difficult).

2. Environmental conditions often change in a rapid and unpredictable manner.